Late Blight of Tomato and Potato

The Pathogen Phytophthora infestans belongs to a group of plant pathogens commonly called “water molds” because of their affinity and special adaptations to water. Until the late 20th century, water molds were classified as fungi. However, as their evolutionary relationships were revealed, they were reclassified within the stramenopiles, a group with many aquatic organisms, such as brown algae.